Reverse circulating foundation underreamer

ABSTRACT

An underreamer mounted on a Kelly for adjustment and rotational driving thereby. A cylindrical housing surrounds the Kelly and mounts a pair of underreamer blades for an outward swinging thereof. A circulating flow is set up through the apparatus for continually removing the debris as it is cut by the reamer blades.

United States Patent v 1 11 3,731,753 Weber 1451 May 8, 1973 REVERSECIRCULATING R2l,241 10 1939 Bertran et al ..l75/285 FOUNDATIONUNDERREAMER 1,731,732 10/1929 Terrell 1 ..175/2s5 1,737,960 12/1929Cramer.... ..l75/285 [76] Inventor 5 :22:; BOX 35564 2,450,223 9/1948Barbour ..l75/285 [22] Filed: Jul 1, 1971 Primary Examiner-James A. Lepink y P pp No 158 943 Attorney-Clarence A. OBricn & Harvey B. Jacobson y57 ABSTRACT An'underreamer mounted on 3 Kelly for adjustment Fieid 285258 and rotational driving thereby. A cylindrical housing surrounds theKelly and mounts a pair of underreamer [56] References Cited blades foran outward swinging thereof. A circulating flow is set up through theapparatus for continually UNITED STATES PATENTS removing the debris asit is cut by the reamer blades. 2,650,072 8/1953 Kammerer ..175/285 9Claims, 9 Drawing Figures l F l 64 i? 54 I r 1 l l Q 4 46 v ll} 42 l I Il 1 1 ti. l a i t: 1 r; 60 1 s 1 I l/ l l 44 /4 Q -/6 3 Sheets-Sheet :3

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/55 I 4/0700 4. Weber- WWW REVERSE CIRCULATING FOUNDATION UNDERREAMERThe present invention is generally concerned with the formation offoundation holes, and moreparticularly relates to an underreamer whichis utilized in forming an enlarged or bellbottom within a foundationhole.

It is a primary object of the instant invention to provide anunderreamer for foundation holes which is constructed so as to enable acontinuing upward flow of the debris as it is cut by the blades therebyavoiding the necessity of periodically withdrawing the reamer from thehole.

Another important object of the instant invention is to provide areamer, mounted on and operable from a standard oil field swivel, whichincorporates underreaming blades automatically adjustable so as toefiect the desired undercutting or belling of the bottom of a foundationhole.

Other objects of the instant invention include the provision ofapparatus which is of a relatively simple although highly uniqueconstruction, durable, easily operated and manipulated, and highlyefficient in the performance of its intended function.

Basically, the objects of the invention are achieved through theprovision of an elongated cylindrical housing having substantially fulllength opposed side openings. The housing pivotally mounts a pair ofelongated depending reamer blades which selectively ex tend outwardlythrough the openings. The movement of the blades is controlled by avertically sliding Kelly movable centrally through the housing andinterconnected with the blades by arms whereby a downward movement ofthe Kelly effects an outward swinging of the blades. The Kelly is inturn telescopically received over a tubular pipe section which, inconjunction with two lower end branches, defines the reverse flow pathfor the debris and drilling mud.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

FIG. 1 is a side elevational view of the apparatus being introduced in afoundation hole;

FIG. 2 is an enlarged cross-sectional view taken sub stantially on theplane passing along line 2-2 in FIG. 1;

FIG. 3 is a cross-sectional view taken substantially on a plane passingalong line 33 in FIG. 2;

FIG. 4 is a top plan view of the apparatus with portions thereof brokenaway for purposes ofillustration;

FIG. 5 is a cross-sectional view taken substantially on a plane passingalong line 5-5 in FIG. 3;

FIG. 6 is a cross-sectional view taken substantially on a plane passingalong line 6-6 in FIG. 3;

FIG. 7 is an elevational view of the apparatus with the reamer bladesextended to illustrate the nature of the operation performed thereby;

FIG. 8 is an enlarged cross-sectional detail of a reamer blade takensubstantially on a plane passing along line 88 in FIG. 2; and

FIG. 9 is a schematic illustration of the mounting of the apparatus.

Referring now more specifically to the drawings, reference numeral 10designates an elongated cylindrical housing which mounts and enclosesthe various operating components of the underreamer.

The housing 10 includes two opposed substantially full height openings12 therein orientated in diametrically opposed relation to each other.The bottom of the housing is closed by a flat base 14 rigid therewithwith the flat base inturn rotatably mounting a bottom plate 16 through acentral pivot forming pin 18 and a series of peripherally arranged ballbearings 20. The bottom plate 16 is significant in that this plate 16will remain stationary at the bottom of a foundation hole while theunderreaming apparatus rotates thereabove in forming the desiredenlarged hole section, thereby avoiding any deepeningor eroding of thebottom of the hole during the underreaming operation.

The upper peripheral edge portion 22 of the cylindrical housing 10 isslightly inward formed and overlies a double walled top closure 24 forthe housing 10. The top closure 24 has a pair of diametrically opposedports 26 defined therethrough, these ports directly communicating withvertical internal channels 28 provided along a major portion of theheight of the housing 10,

terminating in spaced relation above the base plate 14. The channels 28and associated ports 26 are located at right angles to the verticalhousing openings 12 and are specifically provided for the introductionof drilling mud utilized in continuously extracting the dug debrisduring the underreaming operation as shall be explained subsequently.Each of the channels 28 includes a relatively large discharge slot 30 atthe lower end thereof, as well as a series of smaller discharge ports 32for a portion of the height thereof above the bottom slot 30.

The double walled closure 24 at the top of the housing 10 alsoincludes arectangular opening centrally therethrough which slidably receives anelongated rectangular tube or Kelly 34. The Kelly 34 is guidedthroughout its range of vertical movement relative to the housing 10 byfour rollers 36 which rotatably bear against the sides thereof. Each ofthe rollers 36 is mounted for free rolling movement between a pair ofcorner blocks 38, note FIG. 4 in particular for this construction andarrangement. An appropriate stabilizing plate 40 will also be providedwithin the upper portion of the housing 10 about the Kelly 34.

Positioned centrally within the cylindrical housing 10, and slidablyreceiving the Kelly 34 thereover, is a vertically elongated rectangulardischarge tube or pipe 42, the lower end of which directly communicateswith a pair of opposed diverging and downwardly directed branch sections44 which in turn terminate in large mouths orientated slightly above thebase plate 14 for reception of the drilling mud and carried debris tothe pipe 42 and Kelly 34. The discharge pipe 42 and the lower branches44thereon are stabilized within the housing by a pair of bracing plates 46welded to the housing and the branch sections 44. If so desired, thelower portions of the branch sections 44, which lie against opposedportions of the housing wall, can also be directly welded thereto.

The actual reaming or underreaming operation, which results in a bellingenlarging of the bottom of a .foundation hole as illustrated in FIG. 7,is effected by a pair of opposed vertically elongated blades 48. The twoblades 48 are orientated in opposed relation to each other in alignmentwith the opposed housing openings 12 for selective extensiontherethrough. Each blade is mounted by an elongated hinge or pivot pin50 which extends through the upper end thereof and has the opposed endsfixed to the housing or appropriate mounting blocks 50 provided therein.A series of cutting teeth 52, preferably replaceable, are provided alongthe full length of the leading edge of each blade 48. The trailing edgeof each blade 48 tapers inwardly along the length of the blade so as toprovide a relatively narrow lower end on each blade. Noting FIGS. 2 and7 in particular, it will be appreciated that the major portion of eachblade 48 is straight with the bottom section thereof angled slightlyinward, thereby enabling a bell shaping of the hole. FIG. 8 illustratesthe preferred tapered cross-section of the blades 48.

The lateral swinging or adjustment of the two blades 48 is effected by avertical adjustment of the Kelly 34 relative to the housing 10 utilizinga pair of actuating arms 54. Each arm 54 has a first end thereof hingedto one of the blades at the upper end of the lower section designated bythe reference numeral 56. The second end of each arm 54 is orientatedslightly beyond the Kelly 34 and pivotally affixed within a mount 58which is inturn rigidly affixed to the Kelly 34. In this manner, it willbe appreciated that the two actuating arms 54 cross each other at theKelly 34 whereby a maximum inward swinging or collapsing of the blades48 can be effected upon the upward movement of the Kelly 34 relative tothe housing 10. As a safety feature, a pair of cables 60 are engagedbetween each blade 48 and the adjoining end portion of the correspondingarm 54. Likewise, a similar pair of cables 62 will be provided betweenthe Kelly 34 and the inner end portions of the arms 54.

The top of the Kelly 34 is provided with an outwardly projecting flange64 thereabout which is used to connect the Kelly to one or more tubularextensions with the entire unit being operated basically in the mannerof conventional drilling equipment, utilizing a standard oilfield swivel68.

In operation, as the apparatus is being lowered into a foundation hole,the housing 10 will be at its lowermost position on the Kelly 34 withthe blades 48 swung inwardly to their innermost position and the housingsupported from the Kelly 34 through the Kelly engaged pivotally mountedactuating arms 54. When the bottom of the hole is reached, a continueddownward movement of the Kelly against the now stationary housing 10will result in outward swinging of the blades 48. As the blades areswung outward, the apparatus is rotated to form the underreamingdesired. As will be appreciated, the rate at which the blades 48 areextended will vary depending upon the resistance encountered. Therotation is effected through a conventional rotatable driving of theKelly 34 with this rotation being transmitted to the housing 10 by thetorque accommodating Kelly engaging rollers 36. As the rotationalreaming is being effected, it will be appreciated that no deepening oreroding of the bottom of the hole will be effected due to the bottomplate 16 remaining stationary as the housing rotates thereabove. Upon acompletion of the underreaming operation, the entire apparatus can beeasily withdrawn with the initial upward movement of the Kelly 34 firsteffecting an inward collapsing of the blades into the housing 10 throughthe vertical side openings 12 provided therein and a subsequentelevating of the housing and blades.

Specific provision is also made for effecting a continuation dischargeof the cut debris. This is effected by utilizing pressure introduceddrilling mud which flows through the ports 26, along the channels 28 andout the openings 30 and 32 during the actual underreaming operation. THemud mixes with the cuttings being removed from the bottom of the holesand is reintroduced through the bottoms of the two branch sections 44for an upward flowing through the pipe 38, Kelly 34 and Kelly extension66 for discharge through an appropriate ejection line 70. Thiscontinuous extracting of the debris is aided by an air induction systemwhereby air, through an appropriate air line 72, is induced into theKelly at a point approximately twothirds of the distance from the top ofthe hole in a manner so as to cause a vacuum which effects an upwardsucking of the mud and cuttings and a reverse circulation of the debrisoutward of the hole.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention.

What is claimed as new is as follows:

1. An underreamer for foundation holes and the like and comprising avertically elongated hollow housing, said housing including a pluralityof longitudinally extending openings therein, a plurality of blades,means pivotally mounting said blades within the upper portion of saidhousing, said blades extending vertically within said housing inalignment with said openings for selective movement between a firstposition retracted within said housing and a second position swungoutwardly thereof through said openings, an elongated hollow Kellyvertically slidable centrally within said housing, said Kelly projectingvertically above said housing, actuating means interconnecting saidKelly and said blades whereby downward movement of said Kelly relativeto said housing will effect an outward swinging of said blades andupward movement of said Kelly relative to said housing will effect acorresponding inward swinging movement of said blades, and a verticaldischarge pipe located centrally within said housing and telescopicallyreceiving the Kelly thereover, said discharge pipe having an open lowerend and a hollow interior communicating directly with the interior ofthe hollow Kelly for an upward movement of debris therethrough.

2. The underreamer of claim 1 wherein each blade is straight for a majorportion of the length thereof downward from the means pivotally mountingthe blade within the upper portion of the housing, each blade includinga bottom section angled inwardly.

3. The underreamer of claim 1 wherein the actuating meansinterconnecting the Kelly and the blades comprises a plurality of arms,each arm interconnecting the Kelly and one of the blades, said armsbeing pivotally connected at a first end thereof to said Kelly and at asecond end thereof to the corresponding blade, said actuating armsbeings, in each instance, pivoted at a point slightly beyond the Kellythrough a mounting unit rigidly affixed to the Kelly, thereby providingfor a tight inward swinging of the blades upon an upward movement of theKelly relative to the housing.

4. The underreamer of claim 1 wherein said housing includes a pluralityof open ports through the upper end of said housing, said open portscommunicating directly with longitudinally extending channels withinsaid housing for the introduction and downward movement of drilling mudtherethrough, and discharge means toward the lower ends of said channelsfor a discharge of drilling mud from the channels at the underreamingsite.

5. The underreamer of claim 4 including a bottom plate rotatably fixedto the lower end of said housing defining a stationary base for supportof the housing and blades during the rotation thereof.

6. The underreamer of claim 5 wherein said Kelly is rectangular incross-section, the upper end of said housing mounting four rollersengaged with the Kelly peripherally thereabout, the rotation of saidKelly providing a rotating force to said housing through said rollers.

7. The underreamer of claim 4 wherein the lower portion of said verticaldischarge pipe is provided with downwardly and outwardly divergentbranch sections terminating in open ends adjacent the lower end of saidhousing.

8. The underreamer of claim 7 wherein the discharge means in thedrilling mud channels comprises a series of vertically spaced openingscommunicating with the exterior of said housing.

9. An underreamer for foundation holes and the like comprising avertically elongated housing, a plurality of blades, means pivotallymounting said blades within the upper portion of said housing, saidblades extending vertically for selective movement between a firstposition retracted within said housing and a second position swungoutwardly thereof, an elongated hollow Kelly vertically slidablecentrally within said housing, said Kelly projecting vertically abovesaid housing, actuating means interconnecting said Kelly and said bladeswhereby downward movement of the Kelly relative to the housing willeffect an outward swinging of said blades and an upward movement of saidKelly relative to said housing will effect a corresponding inwardswinging movement of said blades, and a vertical discharge pipe locatedcentrally within said housing and telescopically receiving the Kellythereover, said discharge pipe having an open lower end and a hollowinterior communicating directly with the interior of the hollow Kellyfor an upward movement of debris therethrough, and channel meansvertically through said housing for the downward movement of drillingmud therethrough and discharge means toward the lower end of saidchannel means for discharge of drilling mud from the channel means atthe underreaming site.

1. An underreamer for foundation holes and the like and comprising avertically elongated hollow housing, said housing including a pluralityof longitudinally extending openings therein, a plurality of blades,means pivotally mounting said blades within the upper portion of saidhousing, said blades extending vertically within said housing inalignment with said openings for selective movement between a firstposition retracted within said housing and a second position swungoutwardly thereof through said openings, an elongated hollow Kellyvertically slidable centrally within said housing, said Kelly projectingvertically above said housing, actuating means interconnecting saidKelly and said blades whereby downward movement of said Kelly relativeto said housing will effect an outward swinging of said blades andupward movement of said Kelly relative to said housing will effect acorresponding inward swinging movement of said blades, and a verticaldischarge pipe located centrally within said housing and telescopicallyreceiving the Kelly thereover, said discharge pipe having an open lowerend and a hollow interior communicating directly with the interior ofthe hollow Kelly for an upward movement of debris therethrough.
 2. Theunderreamer of claim 1 wherein each blade is straight for a majorportion of the length thereof downward from the means pivotally mountingthe blade within the upper portion of the housing, each blade includinga bottom section angled inwardly.
 3. The underreamer of claim 1 whereinthe actuating means interconnecting the Kelly and the blades comprises aplurality of arms, each arm interconnecting the Kelly and one of theblades, said arms being pivotally connected at a first end thereof tosaid Kelly and at a second end thereof to the corresponding blade, saidactuating arms beings, in each instance, pivoted at a point slightlybeyond the Kelly through a mounting unit rigidly affixed to the Kelly,thereby providing for a tight inward swinging of the blades upon anupward movement of the Kelly relative to the housing.
 4. The underreamerof claim 1 wherein said housing includes a plurality of open portsthrough the upper end of said housing, said open ports communicatingdirectly with longitudinally extending channels within said housing forthe introduction and downward movement of drilling mud therethrough, anddischarge means toward the lower ends of said channels for a dischargeof drilling mud from the channels at the underreaming site.
 5. Theunderreamer of claim 4 including a bottom plate rotatably fixed to thelower end of said housing defining a stationary base for support of thehousing and blades during the rotation thereof.
 6. The underreamer ofclaim 5 wherein said Kelly is rectangular in cross-section, the upperend of said housing mounting four rollers engaged with the Kellyperipherally thereabout, the rotation of said Kelly providing a rotatingforce to said housing through said rollers.
 7. The underreamer of claim4 wherein the lower portion of said vertical discharge pipe is providedwith downwardly and outwardly divergent branch sections terminating inopen ends adjacent the lower end of said housing.
 8. The underreamer ofclaim 7 wherein the discharge means in the drilling mud channelscomprises a series of vertically spaced openings communicating with theexterior of said housing.
 9. An underreamer for foundation holes and thelike comprising a vertically elongated housing, a plurality of blades,means pivotally mountiNg said blades within the upper portion of saidhousing, said blades extending vertically for selective movement betweena first position retracted within said housing and a second positionswung outwardly thereof, an elongated hollow Kelly vertically slidablecentrally within said housing, said Kelly projecting vertically abovesaid housing, actuating means interconnecting said Kelly and said bladeswhereby downward movement of the Kelly relative to the housing willeffect an outward swinging of said blades and an upward movement of saidKelly relative to said housing will effect a corresponding inwardswinging movement of said blades, and a vertical discharge pipe locatedcentrally within said housing and telescopically receiving the Kellythereover, said discharge pipe having an open lower end and a hollowinterior communicating directly with the interior of the hollow Kellyfor an upward movement of debris therethrough, and channel meansvertically through said housing for the downward movement of drillingmud therethrough and discharge means toward the lower end of saidchannel means for discharge of drilling mud from the channel means atthe underreaming site.